SOLVED. 2 young people fall in love on planet-sized space ship. [s]

[wanderer]

Helping a friend look for a sci-fi novel set in the future.

All former earthlings are living on a traveling planet-sized space ship. Something goes wrong during a drill of sorts and two kids (youths?) crash land on a planet they have never heard of. They despise each other at first, but pull together in the fight for their lives, and, eventually, fall in love.

There is some emphasis placed on the female main character's green dress, and she's wearing that dress on the cover of the book.

(Asking for a friend.)

[Becca]

These Broken Stars by Amie Kaufman?
Cover with green dress:

[wanderer]

Seriously! How did you do that so quickly? Thanks a bunch!

My friend texted me, "That’s totally it🤭🤭🤭 I’m so pleased thank you!!!"